Examination of the efficiency of retrofitting methods through fragility analysis

Abstract

Turkey had several devastating earthquakes throughout its history as it is located in a highly seismically active region. Thus, seismic evaluation and retrofitting of the existing structures to decrease the potential damage of the future earthquakes is an essential part of the earthquake relief plans. The aim of this study is to examine the efficiency of widely used two retrofitting methods of existing structures through fragility analysis. Fragility curves are useful tools to show the probability of structural damage due to earthquakes as a function of ground motion indices. Fragility curves of a hypothetical residential building which represents the existing building stock have been generated. Furthermore, fragility curves of two retrofitted building have also been obtained. The first one is a frame with jacketed columns and the second one has shear walls added to the existing frame. Fragility curves have been obtained based on both local and global damage criteria limits in terms of interstory drift ratio. The obtained damage probabilities have shown that the damage criteria either local or global which are used for generation of fragility curves are significantly effective on the results. Differences in damage probability indicate the importance of the damage criteria and corresponding limits used for the determination of damage probability.